I Recently bought a Mt Vernon Insert, Was told it would heat a 3800 sq f house. My home is aproximately 1300 and can't seem to heat to the back of the house. The livingroom, dinning room and Kitchen are fine as it is an open concept. It keeps these rooms at 71 decrees the back of the house is at 62 give or take. I keep the setting at Low to medium Low, can't see if there would be much more saving if you ran it higher then this to oil. Is this realistic?